take potatoes, preferably small ones parboil them with the skins on, let cool slowly a few hours or even better overnight. If you refrigerate or put into cold water, they get too sticky.
Take a knife and scratch off the skins, they should slip off without having to take any of the flesh from the potato.
Grate potatoes by hand, a cheese grater works fine. Machine grated potatoes are too mushy.
In an iron skillet (it will stick to stainless steel) melt butter.
Form grated potatoes into cake, and put into hot pan. cook on a medium heat about 5 to 7 minutes on a side, covered.
To turn cakes, the traditional way is to slide out of the pan onto a plate. Put another plate upside down on top, and flip the whole mess over very quickly, then slide back into pan with new butter.
The Röschti is usually about 5 to 6 inches wide, and 1/2 to 3/4 inches thick. It should have a crispy outside and a very light, fluffy inside.
This is the basic version. You might mix onions or herbs in with the potatoes, or you can top it off with 2 eggs or with cheese -but use a Swiss cheese. I made my lunch with a topping of mixed Emmentaler and Le Gruyere.